\begin{tikzpicture}
    \tkzDefPoints{0/0/O, 4/0/A}
    \tkzDefPoint(55:4){B}
    \tkzDefLine[bisector](A,O,B)  \tkzGetPoint{e}
    \tkzDefPointOnLine[pos=0.8](O,e)  \tkzGetPoint{E}
    \tkzDefPointBy[projection= onto O--A](E)  \tkzGetPoint{C}
    \tkzDefPointBy[projection= onto O--B](E)  \tkzGetPoint{D}

    \tkzDrawSegments(O,A  O,B  O,e  E,C  E,D  C,D)
    \tkzMarkRightAngle(E,C,A)
    \tkzMarkRightAngle(E,D,B)
    \tkzLabelPoints[below](O,A,C)
    \tkzLabelPoints[above](B,E)
    \tkzLabelPoints[above left](D)
\end{tikzpicture}

